Development of an Electro Tribological Instrument to Examine the Deterioration of the Robot- Bearing

The increasing electrification of robotic systems poses significant tribological challenges, particularly for bearing components. This study investigates the impact of direct current (DC) on the wear behaviour and tribological characteristics of robotic bearing systems. Experiments were conducted using a Ball-on-Disc tribometer under various DC current levels, lubrication conditions, and loading parameters. Results indicate that DC current significantly influences electrical impedance, friction coefficient, and wear scar diameter. Increased current intensity reduces impedance due to diminished lubricant viscosity and enhanced metal-to-metal contact. Friction initially decreases at moderate currents due to electrostatic repulsion but increases at higher currents due to electrostatic breakdown. Wear scar analysis reveals a decrease in scar diameter with increasing current, attributed to oxide layer formation. While load was found to be a significant factor influencing wear loss, the effects of sliding speed and current on wear and friction were less pronounced. These findings provide crucial insights into the tribological mechanisms in electrified robotic systems and highlight the need for optimized load and lubrication conditions to improve component durability.